I suppose that this is why we're all hooked on the case. Every avenue leads to half a dozen others. Every scenario suggests half a dozen others.
I do take your point about his 'friend' though. After all you would think that she would be overjoyed at the thought of her man becoming successful. I wonder if he now felt that he could get her off the streets but she didn't want to.

My search was performed on WorldCat at www.worldcat.org ("the world's largest library catalog") using the search string SUBJECT: Francis Thompson (1859-1907) biograhy / filtered by format Book and language English. The result list was "about 20" and included books, e-books, and a couple of database articles of the reference type. Most of the books were originally published between 1912 and 1988, and most had multiple editions. I have noted down how many libraries hold each title, as this is often an indication of the quality of a nonfiction book.

I hope it will help Casebook readers who want to learn more about the life of Francis Thompson, seminary and medical school student, poet, author, street-dweller, and recent Ripper suspect.

Boardman, Brigid M.Between Heaven and Charing Cross: the Life of Francis Thompson
1988, Yale University Press. Available as an ebook. (9 editions, held by 477 libraries.) She also wrote the article "Thompson, Francis Joseph (1859-1907), poet and writer" for the Oxford Dictionary of National Biography Online.

Hind, C. Lewis. Naphtali: being influences and adventures while earning a living by writing, with forty-four illustrations. 1926, John Lane, The Bodley Head. Available as an ebook. (13 editions, held by 141 libraries.)

Kelly, Michael A. (Note: search by Thompson, Francis.)
Author of a biographical sketch on the poet included in a reprinted edition of Thompson's The Hound of Heaven (originally 1916) 2015, Forgotton (sic) Books. (151 editions, held by 748 libraries.)

Meynall, Everad. The Life of Francis Thompson. (1913). This edition is a reprint: 1971, Scholarly Press. (64 editions, held by 710 libraries.) This edition is also available as an e-book, held only by the HathiTrust Digital Library.

Thomson, John. (2 books)
-- Francis Thompson: Poet and Mystic. 1974, Haskall House. (13 editions, held by 179 libraries.)
-- Francis Thompson, the Preston-born poet: with notes on some of his works. 1977, Norwood Editions. Note: "Reprint of the 1912 edition, published by A. Halewood, Preston, England." I think Thomson likely is the editor of the older book in this reprint and probably added the notes. (25 editions, held by 162 libraries.)

Thank you PCdunn for compiling this list of books about the Life of Francis Thompson. There is much to read but each book adds to the knowledge base. Here are a selection of books that I have sourced in my research. Some of these books are on Thompson and some are on the Ripper crimes. It is not an exhaustive list and some of the titles, that you have already listed, are included.

Pcdunn,
The articles I mention are taken from a colonial newspaper,the Jamaica Gleaner.
While all refer to lectures given in Kingston,Jamaica,it seems the persons mentioned were held in high esteem,and their knowledge from a personell study of Francis Thompson.
W hether they wrote books or left evidence of their studies,I do not know.
I have not yet read every article concerning Thompson,nor tried to follow up on the persons mentioned.
Regards.